The present study aims to understand changes in health problems, health complaints and coping strategies, during the obesity treatment process with qualitative and quantitative data. Thirty bariatric patients were interviewed before bariatric surgery and at a 12-month follow-up, and fulfilled self-report measures about health problems, health complaints and coping strategies before surgery, at 6-and 12-month follow-ups. Before surgery, failure cases differ from success on the conceptualization of obesity, However, there are no other differences between groups. At 6-and 12-month follow-ups, failure cases had the highest BMI, health problems and complaints and less % EWL than success cases. One year after the surgery, one in each three persons did not lose the expected weight, i.e., are failure cases. Before surgery, there are no differences between success and failure cases in the report of health problems, health complaints and coping strategies, but they have different conceptualizations of their obesity and treatment. One year after the surgery, success cases understood bariatric surgery as an important moment in their lives related to their expected results, whereas failures valued unexpected dimensions and still waiting for a miracle surgery without their personal commitment. Accordingly, it is necessary to consider lifestyle changes in the obesity treatment process.